Stacker



R. F. BARBER Aug. 17, 1965 STACKER 6 Sheets-Sheet 1 Filed Feb. 27, 1962 R. F. BARBER Aug. 17, 1965 STACKER 6 Sheets-Sheet 2 Filed Feb. 27. 1962 HL E1" BARBER Aug. 17, 1965 STACKER 6 Sheets-Sheet 5 Filed Feb. 27, 1962 R. F. BARBER Aug. 17, 1965 STACKER 6 Sheets-Sheet 4 Filed Feb. 27, 1962 R. F. BARBER Aug. 17, 1965 STACKER 6 Sheets-Sheet 5 Filed Feb. 27. 1962 j "TTI-111| lllllll:

R. F. BARBER Aug. 17, 1965 STACKER 6 Sheets-Sheet 6 Filed Feb. 27. 1962 NNW @www @www @Nm United States Patent O 3,291,116 STACKER Ralph F. Barber, Ehnhnrst, Ill., assigner to Miller Wrapping di Sealing Machine Company, a corporation of Illinois Filed Feb. 27, 1962, Ser. No. 175,915 11i Claims. (Cl. 271-79) This invention relates to article stacking means and, more particularly, means for stacking limp film sheets such as bags or the like.

An object of this invention is to provide a new and improved stacking device.

`Another object of this invention is to provide a stacking device for limp sheets, such as bags or the like, in which timing of the stacking means is not critical with respect to an adjacent machine which is feeding the sheets to be stacked.

A further object of the invention is to provide a stacking device in which the leading part of succ/essive sheets are supported and fed out over a base or platform on which the sheets are stacked with the leading part of the sheet held impositively only by friction whereby the stacking means may continue on and the sheet is released without any positive control.

` Other objects of the invention are to provide a stacking device as defined in the preceding paragraph having a plurality of supports for individually supporting the leading part of a sheet with a supply of the supports being maintained in a storage station awaiting use as required to handle any desired length of sheet and means are provided Vfor releasing air between a sheet being i placed on the stack and the top of the stack,` including a transversely sloped platform or base and means are provided for holding the sheet stack in position as a successive sheet is drawn onto the stack.

Furtherobjects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

FIGURE l is a fragmentary side elevational view of the stacking device with parts of the bag feeding machine shown broken away; j 3 FIGURE 2 is a fragmentary end elevational view of the stacking device looking at the left-hand end of FIG- URE l; i t

FIGURE 3 is a diagrammatic view showing the operation of the stacking device; FIGURE 4 is a vertical section'on an enlarged scale taken along the center line of the stacking device toward the right-hand end thereof as viewed in FIGURE l and showing a plurality of bag supports in various positions provided in the machine;

FIGURE 5 is a plan view of the structure shown in FIGURE 4; FIGURE 6 is a plan view of a single sheet support on an enlarged scale shown in association with the endless chain members providing movement thereof;

FIGURE `7 is an end view of the mechanism shown in FIGURE 6; FIGURE `8 is a side elevational view of the mechanism shown in FIGURE 6;

FIGURE 9 is a detail view of the adjustment mechanism for controlling the cycling of the stacking device;

FIGURE 10 is a diagram ofthe circuitfor obtatining operation of the stacking device; and i FIGURE l1 is a showing of a modified form of plat' form or base for the sheets. l i j While this invention is susceptible of embodiments in many different forms, there is shown in the drawings andi will herein be describedA in detail an embodiment of the; invention together with a modication thereof with the understanding that the present disclosure is to be considered as an exemplifcation of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. .The scope of the invention will be pointed out in the appended claims.

The stacking device as disclosed herein is suitable for stacking bags made of limp film which comprise two sheets of material secured along their edges except for an open end and which issue from the bag-making machine in flat form.` The device is capable of use with a bag-makingmachine, such as shown in Weist Patent No. 2,882,956, with a part of such machine being shown in FIGURE l. A motor 1li drives a shaft 11 and a clutch 12 with the shaft 11 having a belt drive connection 13 to one roller of a pair of feed rollers 1d and 1S which advance the formed bag past a pair of cutters 16 and 17 with the cutter 17 being movable to cut off the bag. As disclosed in the Weist patent, the clutch 12 includes a switch-operating member 18 for controlling the length of bag that is made.

The stacking device is indicated generally at Zt) and comprises a stand 21 suitably constructed to engage the floor and includes a pair of side supports 22 and 23 mounting the platform or base of the stacking device for movement between the normal operative position shown in full line in FIGURE l and an out-oftheway position shown in broken line in FIGURE l.

The platform for the stack of sheets is indicated at 24 and comprises a generally rectangular plate extending for the length and width of the stacking device, which is supported from a pair of side plates 25 and 26 which extend downwardly in spaced parallel relation with the side supports 22 and 23 of the stand. The plates 25' and E6 are connected by a tube 27 which has pins 28 and 29 at its ends whereby the platform can be pivoted between the positions shown in FIGURE l.

The stacking device includes continuously driven endless'chains which run along each side of the stacking device with one chain being indicated at 30 and the other at 31 in FIGURE 2. The chain 36 passes about a sprocket 32 at one end of the stacking `device and a sprocket 33 at the opposite end which is located at a loading station adjacent the discharge end of the bag-making machine. The chain 31 passes about a corresponding pair of sprockets 34 and 35. As shown in FIGURE 3,

this results in the chains having a lower reach ywhich is driven in a direction travelling away from the loading station and at a level spaced above the level of the platform 24 andan upper reach for return of the supports to a storage station at an upper level to be subsequently described.

The drive .for `the chains is derived from a motor 36 having avariable `speed pulley thereon which drives a belt 37 passing about a pulley 33. The pulley 38 is on a shaft with a sprocket driving a chain 39 which engages with a sprocket le on a shaft i1 which carries the aforementioned sprocket-s 32 .an 34. The speeld of the drive can be varied by manipulation of the hand wheel l2 to vary the distance between the split pulley and the pulley 38, as well known in the art.

At this point reference may be made to FIGURE 3 which shows the operation diagrammatically. A sheet for .bag is shown in full line issuing from the feed rolls 14 and 15 ofthe bragnnaking machine to the loading station for the stacking device,` in ywhich :the leading part of the sheet extends forwardly. A subsequent position of the bag is shown in broken line in which the leading par-t of the bag is frictionally ywrapped about a support member whichcarries it ou-t `across the platform for dropping onto the bag stack supported on the platform 214. Three different -bag supports are shown in FIGURE 3 with each ofthe Patent-eel Aug. 17, 1965- supports comprising a pair of rotds or bars d and The bars waiting at the loading station are identified as 45a yand 46a, the bars in an oper-ating cycle are .identified as 45h and 46h and a pair' of bars at a stat-ion awaiting advance to the loading station are identified as 45C and 46c.

The bars of each support `are arranged for selective drive engagement with the chains Sil and 3l travelling along the sides of the platform.

Reference may now be made to FIGURES 4, 6 and 7, tor a more ydetailed description of one of the supports for the leading part of a sheet or bag. The pair of bars 45 and d5 extend between a mounting bracket 47 at one of their ends and another mounting bracket at the opposite ends thereof. The bar 45 is rotatably mounted in the bracket 47 and has a tubular part {if} and a chain engaging sprocket 5G secured thereto for rotation therewith, while the other end of the bar is rotatably mounted in tl e "bracket 4S and has a chain engaging sprocket 5l secured thereto for rotation with the bar.

Each bag `Support has brake means associated therewith `for determining whether the sprockets 5@ and 5l may Afreely rotate as driven by the chains or whether the sprockets will be held against rotation relative -to the brackets 47 and 43. This brake device comprises a generally U-shaped brake arm 52 pivoted at S3 to the bracket 47 and carrying a curved steel brake member 54 which may er1-gage against the tubular part rotatably afxed to the support bar The brake device also includes a iirst detent 55 engagcalble at locations ,and times described hereinafter to release the brake and a second detent 5u 4functioning similarly to the detent S5 when engaged as described subsequently. The brake arm 52 is normally urged to an on position by a spring 57 engageld between the brake arm and the bracket 47.

Trailing parts of the brackets 47 and d8 mount the support bar 46. ln order to hold the bag support on the chains an upper part of the brackets 47 and d8 mount shoes o@ and 61 which slide against the upper parts of the chains when the cl ains are moving relative thereto and which travel with the chains at other times. vSimilar shoes 62 engage both above and below the chains at the rear of the brackets 47 and 4S.

The sets of bars of the bag supports in FIGURE 4 have been identified similarly to those in FIGURE 3 to show various positions of the supports with `a pair olf additional bag supports shown in la storage station.

At the loading station, a support is held in position to receive a leading part 65 of a bag by engagement of the leading detent 55 of a support by a latch 66 to throw oit the brake member 54. This latch is carried on an arm 67 pivoted at o8 on the frame and operated through a link 69 by a solenoid 70. When the solenoid 7? Iis actuated, the latch o6 is pivoted in a clockwise direction, as viewed in FlGURE 4, to release the detcnt 55" of the brake device with the result that the lbrake member 54 can engage the tubular part d@ to hold the sprockets against rotation relative to the chains Sil and 3l and the support is carried along with the chains to move through a bag or sheet stacking cycle. This con'dition is shown in FIGURE 4 with the support having bars @5b and tub in which the leading vpart 65 of the sheet has wrapped about the bar 45h. lt will be noted by comparison of these two positions that the angular disposition of the bars 45 and 46 has also changed. When the bars are at the loading station, they are in vertically spaced relation with one above the other to permit easy entry of the leading part 65 of a bag therebetween and when .the support bars move onto the lower reach of the chain, the bars are in horizontal spaced relation to facilitate a good friotional engagement with the leading part of a bag.

The support having bars 45C and 46c is held at a position immediately preceding the loading station by a latch 7l which engages the trailing ldetent 56 of the brake arm to release the brake and `permit rotation of the sprockets and 51 Without resultant movement of the support,

with the support also actually being held by the latch 71. The latch '7l is mounted for upward releasing movement on a lever l pivoted to a trame support at 73 and is pulled upwardly by a solenoid 74. When the latch 7l is pulled upwardlyy another latch '75, mounted on the lever 72, is moved dow wardly to engage and hold a succeeding support until such time as the latch 7l moves down into position to hold a support. When this occurs, the latch 75 moves up to permit advance of a support to the latch 7l.

An added supply of bag supports can be stored immediately preceding the latches 7l and 75 as provided by an idler belt 76 overlying the trailing detents 56 of the bag supports for engagement therewith to throv/ off the brakes rlfhe belt 76 is an idler and is mounted on a fr Lne 77 for vertical movement, with the frame being t ported on a pair of links 7S and 79 which are pivoted on a frame member When a support is to move to the latch "il, a solenni is actuated to raise the frame 77 and the belt 7 6 to again permit the brakes 5ft to be set to cause advance of the supports until the leading support is engaged by the latch i5 and tien by the latch '71. A bar extends through this area to be engaged by a roller on the bracket for support of the bracket.

The circuit for operation o the solenoids 70, 74 and 8l referred to is shown in FlGURE 10 in which the circuit to the solenoid 70 for release of the latch 66 is operated from a switch operated from the control of the bag-making machine and which is arranged to operate a short time interval after the bag-making machine has started to feed a bag beyond the cutting knives 16 and 17 by operation of the feed rolls i4 and 15. The solenoid 74 for release of the latch 7i is operated by a switch 85 operated by the movable knife 17 on the bag-making machine to send a support to the loading station after a preceding bag has been cut olf by the bag-making machine. The solenoid 8l is operated by a switch 87 which is positioned to be engaged by the lever 72 during the actuation and release of the latch 71 so as to raise the idler belt 76 and permit advance of bag supports to the position of the latch 7l.

The actuating member i3 shown in FIGURES 1 and 9 lcorresponds to the member 35 of the Weist patent for determining the end of the feeding movement of the bagmaking machine by engagement with a switch as described in the patent, with the return of this member to a zero position of engagement with a plate 9i) secured to a shaft 91. An operator 92 for the switch 35 controlling the latch release solenoid 70 is also movable with the switch operating member 1S and the position of the switch 85 is variable under the control of a hand 0perated worm 93 driving a gear 94 on the shaft 91. The switch 85 is carried on a collar 95 loose on the shaft 91 whereby it is rotatably positioned from rotation of the worm 93 through a gear 96 fixed to the shaft meshing with a gear 97 on a shaft 9S carrying a gear 99 meshing with a gear lll@ Xed to the sleeve 95. The gears 96 and i are of slightly different size so as to provide a different ratio of adjustment between the switch 85 and the zero plate 9d to obtain variable timing of actuation of a support for the leading part of a bag with respect to the total length of bag being fed to the stacking device. In thisway, it isl made certain that the leading part of a bag will be supported until the bag is fully placedY on top of the stack before the support bars 45 and 46 leave the leading part of the bag and travel onto the upper reach of the chains. The adjustment referred to is maintained by friction retarding springs 101.

It will be seen from the foregoing structure that a construction is provided in which the timing of operation is` not critical due to the impositive frictional engagement of a leading part of a bag with the bars 45 and 46 of a support. A leading part of the bag will be fed between these bars and the bars will then commence to move to carry the leading part of the bag forwardly over the stack asthe bag is still being fed from the bag-making machine.

rOnce the bag is cut olf by the knives 16 and 17, the bag will settle onto the stack and the leading part of the bag will slide out of and away from engagement with the bars 4S and 46 to the left of the position shown for bars 45b and 4611 in FIGURE 3. Because of the storage provided for a number of supports, it is possible to properly feed out bags of any length, since one, two, three or more bag supports can be moving about the total path of movement at the same time, with one support leaving the leading edge of a bag, while the next support is receiving another bag, and a further support can be still travelling to the storage location at idler belt 76.

In order to hold the stack in place as a bag is being fed thereonto, a pair of pads may be provided one at each side of the platform with one of these being shown in FIGURE 1. The pad includes a gripper 105 carried on an arm 106 pivoted at 107 with actuation from an air cylinder 108 whereby as a sheet is approximately lined up with the stack the cylinder 108 is operated to raise the gripper which deects the edge part of the bag until the gripper is on top of the sheet and the gripper then descends upon release of air to the cylinder 108 to de scend onto the top of the stack. The pivot 107 is a shaft extending to the other side of the machine where a similar gripper 105 is located adjacent the edge of the platform. This upward movement of the grippers 105 also aids in expelling air from under the individual bag so that it will better move into place on the stack.

An alternate embodiment of the platform 24 is shown in FIGURE 11 in which the platform is raised along its center with the sides thereof sloped as indicated at 24a and 24b and with the platform actually being defined by a pair of conveyor belts 110 and 111 which can be suitably driven in a manner known in the art to, at the dcsired interval, be energized to move a stack from the platform. With the highest part of the platform along the longitudinal center line thereof, a bag will settle upon the stack with the center part thereof irst engaging the stack and the bag settling progressively toward the edges to gradually expel air from beneath the bag.

I claim:

1. A device for stacking relatively limp lengths of material comprising, a platform on which the material is stacked, a pair of endless members traveling one at each side of the platform, and a pair of bars extending transversely of the platform and mounted at their ends to the members, said bars being in fixed spaced apart relation to have the leading part of a length of material threaded therebetween whereby said material is frictionally held by the bars for movement therewith.

2. A bag stacker for stacking bags issuing from bag making machinery having bag advancing means for advancing a bag at a rst rate of speed comprising, a stacking platform, and means for frictionally carrying the leading part of a bag to a point to have the bag disposed at a stacking location above the platform including a member traveling along the platform on which the leading part of the bag is supported for movement therewith and relative thereto, and means for advancing said member at a rate of speed greater than said first rate to have the member leave the bag at said stacking location.

3. A bag stacker as defined in claim 2 including a movable member for holding a stack of bags in place.

4. A stacking device for sheets of limp material comprising, a base on which the sheets are stacked, a pair of continuously driven endless members traveling one at each side of the base with a lower reach traveling away from a loading station and an upper return each, a support for the leading part of a sheet comprising a pair of bars in xed spaced apart relation extending transversely of the base and operatively connected to the members for selective movement with the members, means for holding the rsupport at the loading station with the bars located generally one above the other for movement of a leading part of a sheet therebetween, and means releasing the support for travel along the lower reach with one bar trailing the other to obtain good frictional engagement with the sheet.

5. A stacking device as claimed in claim 4 in which a plurality of supports are releasably associated with said endless members, and means for storing all but one of said supports at a location awaiting successive advance to said loading station.

6. A device for stacking sheets of material comprising, a base having an end disposed adjacent a machine from which the sheets are fed, a pair of continuously driven endless chains located one at each side of said base and passing around sprockets at ends of the base to dene upper and lower chain reaches, a support for a sheet comprising a bar extending transversely of the base, mounting means at each end of the bar comprising a bracket rotatably mounting the bar, a sprocket attached to the bar and in engagement with the chain, and brake means movably mounted on the bracket for selective engagement with the bar whereby engagement of the bar prevents rotation of the bar and sprocket to cause the bar to travel with` the chains and release of the brake permits rotation of the sprocket sor that the chain can move relative thereto.

7. A device as defined in claim 6 in which the brake means is yieldably urged to an engaging position, including means selectively engageable with the brake means at an` end of the base to hold the brake released until a sheet is received by the bar.

8. A device as defined in claim 7 including other means selectively engageable with the brake means at a bar storage station to hold the brake released until a bar is required at said end of the base.

9. A device as defined in claim 8 in which` the sheet support comprises a second bar in spaced parallel relation with the aforementioned bar.

iti. A device for stacking sheets of material comprising, a base having an end disposed adjacent a machine from which the sheets are fed, a pair of continuously driven endless members located one at each side of said base and Ahaving upper and lower reaches, a support for a sheet comprising a bar extending transversely of the base, mounting means at cach end of the bar comprising a bracket rotatably mounting the bar, a rotatable member attached to the bar and in engagement with one of the endless members, and brake means movablly mounted on the bracket for selective engagement with the bar whereby engagement of the bar prevents rotation of the bar and rotatable member to cause the bar to travel with the endless members and release of the brake permits rotation 0f the rotatable member so that the endless member can move relative thereto.

References Cited bythe Examiner UNITED STATES PATENTS` 2,788,210 4/57 sperry 271-79 X 2,795,861 6/57 Black 271-79 X 2,645,480 7/53 Long 271-74 3,044,772 7/62 Trenner 271-68 ROBERT B. REEVES, Acting Primary Examiner.

EUGENE R. CAPAZIO, RAPHAEL M. LUPO,

Examiners. 

1. A DEVICE FOR STACKING RELATIVELY LIMP LENGTHS OF MATERIAL COMPRISING, A PLATFORM ON WHICH THE MATERIAL IS STACKED, A PAIR OF ENDLESS MEMBERS TRAVELING ONE AT EACH SIDE OF THE PLATFORM, AND A PAIR OF BARS EXTENDING TRANSVERSELY OF THE PLATFORM AND MOUNTED AT THEIR ENDS TO THE MEMBERS, SAID BARS BEING IN FIXED SPACED APART RELATION TO HAVE THE LEADING PART OF A LENGTH OF MATERIAL THREADED THEREBETWEEN WHEREBY SAID MATERIAL IS FRICTIONALLY HELD BY THE BARS FOR MOVEMENT THEREWITH. 